Pediatric cardiology remains a field with relatively few researchers, basic or clinical. The reasons for this are complex and may relate to trends affecting many pediatric subspecialities. Nevertheless, the Children's Hospital of Philadelphia (CHOP) cardiology research programs overall have continued to demonstrate outstanding growth, offering a broad array of research training opportunities for the postdoctoral fellows in this Program. We seek to train physicians and basic scientists in molecular therapeutics for heart disease in children. It is our expectation that our trainees will become creative cutting edge researchers whose efforts will lead to new therapies and diagnostic techniques for pediatric cardiology. Our working definition of molecular therapy has now been broadened to enable this goal and includes training opportunities in four major areas: I) Experimental pharmacology and gene therapy; II) Molecular genetics and development; III) Cardiovascular pathophysiology, IV) Imaging, outcomes, clinical pharmacology, and clinical epidemiology. There has been enthusiastic interest in this T32 program from its inception including a strong minority recruitment. An outstanding cohort of productive trainees has already graduated from our Program. The composition of our proposed trainee group for the Program renewal is planned to include 4 physicians, who will be recruited from our pediatric cardiology fellowship, and 3 Ph.D. scientists or non-pediatric cardiology physician scientists. We have increased by one the number of physicians because of the increase in interest among our cardiology fellows at CHOP.